 // unique_ptr implementation -*- C++ -*-
 
 // Copyright (C) 2008, 2009, 2010 Free Software Foundation, Inc.
 //
 // This file is part of the GNU ISO C++ Library.  This library is free
 // software; you can redistribute it and/or modify it under the
 // terms of the GNU General Public License as published by the
 // Free Software Foundation; either version 3, or (at your option)
 // any later version.
 
 // This library is distributed in the hope that it will be useful,
 // but WITHOUT ANY WARRANTY; without even the implied warranty of
 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 // GNU General Public License for more details.
 
 // Under Section 7 of GPL version 3, you are granted additional
 // permissions described in the GCC Runtime Library Exception, version
 // 3.1, as published by the Free Software Foundation.
 
 // You should have received a copy of the GNU General Public License and
 // a copy of the GCC Runtime Library Exception along with this program;
 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 // <http://www.gnu.org/licenses/>.
 
 /* * @file unique_ptr.h
  *  This is an internal header file, included by other library headers.
  *  You should not attempt to use it directly.
  */
 
 #ifndef _UNIQUE_PTR_H
 #define _UNIQUE_PTR_H 1
 
 #include <bits/c++config.h>
 #include <debug/debug.h>
 #include <type_traits>
 #include <utility>
 #include <tuple>
 
 _GLIBCXX_BEGIN_NAMESPACE(std)
 
   /* *
    * @addtogroup pointer_abstractions
    * @{
    */
 
   /// Primary template, default_delete.
   template<typename _Tp>
     struct default_delete
     {
       constexpr default_delete() { }
 
       template<typename _Up, typename = typename
            std::enable_if<std::is_convertible<_Up*, _Tp*>::value>::type>
         default_delete(const default_delete<_Up>&) { }
 
       void
       operator()(_Tp* __ptr) const
       {
     static_assert(sizeof(_Tp)>0,
               "can't delete pointer to incomplete type");
     delete __ptr;
       }
     };
 
   // _GLIBCXX_RESOLVE_LIB_DEFECTS
   // DR 740 - omit specialization for array objects with a compile time length
   /// Specialization, default_delete.
   template<typename _Tp>
     struct default_delete<_Tp[]>
     {
       constexpr default_delete() { }
 
       void
       operator()(_Tp* __ptr) const
       {
     static_assert(sizeof(_Tp)>0,
               "can't delete pointer to incomplete type");
     delete [] __ptr;
       }
     };
 
   /// 20.7.12.2 unique_ptr for single objects.
   template <typename _Tp, typename _Dp = default_delete<_Tp> >
     class unique_ptr
     {
       // use SFINAE to determine whether _Del::pointer exists
       class _Pointer
       {
     template<typename _Up>
       static typename _Up::pointer __test(typename _Up::pointer*);
 
     template<typename _Up>
       static _Tp* __test(...);
 
     typedef typename remove_reference<_Dp>::type _Del;
 
       public:
     typedef decltype( __test<_Del>(0)) type;
       };
 
       typedef std::tuple<_Tp*, _Dp>     __tuple_type;
       __tuple_type          _M_t;
 
     public:
       typedef typename _Pointer::type   pointer;
       typedef _Tp                       element_type;
       typedef _Dp                       deleter_type;
 
       static_assert(!std::is_pointer<deleter_type>::value,
             "constructed with null function pointer deleter");
 
       // Constructors.
       constexpr unique_ptr()
       : _M_t()
       { }
 
       explicit
       unique_ptr(pointer __p)
       : _M_t(__p, deleter_type())
       { static_assert(!std::is_pointer<deleter_type>::value,
              "constructed with null function pointer deleter"); }
 
       unique_ptr(pointer __p,
       typename std::conditional<std::is_reference<deleter_type>::value,
         deleter_type, const deleter_type&>::type __d)
       : _M_t(__p, __d) { }
 
       unique_ptr(pointer __p,
       typename std::remove_reference<deleter_type>::type&& __d)
       : _M_t(std::move(__p), std::move(__d))
       { static_assert(!std::is_reference<deleter_type>::value,
               "rvalue deleter bound to reference"); }
 
       constexpr unique_ptr(nullptr_t)
       : _M_t(pointer(), deleter_type())
       { }
 
       // Move constructors.
       unique_ptr(unique_ptr&& __u)
       : _M_t(__u.release(), std::forward<deleter_type>(__u.get_deleter())) { }
 
       template<typename _Up, typename _Ep, typename = typename
     std::enable_if
       <std::is_convertible<typename unique_ptr<_Up, _Ep>::pointer,
                    pointer>::value
        && !std::is_array<_Up>::value
        && ((std::is_reference<_Dp>::value
         && std::is_same<_Ep, _Dp>::value)
            || (!std::is_reference<_Dp>::value
            && std::is_convertible<_Ep, _Dp>::value))>
          ::type>
     unique_ptr(unique_ptr<_Up, _Ep>&& __u)
     : _M_t(__u.release(), std::forward<deleter_type>(__u.get_deleter()))
     { }
 
 #if _GLIBCXX_DEPRECATED
       template<typename _Up, typename = typename
     std::enable_if<std::is_convertible<_Up*, _Tp*>::value
                && std::is_same<_Dp,
                        default_delete<_Tp>>::value>::type>
     unique_ptr(auto_ptr<_Up>&& __u)
     : _M_t(__u.release(), deleter_type()) { }
 #endif
 
       // Destructor.
       ~unique_ptr() { reset(); }
 
       // Assignment.
       unique_ptr&
       operator=(unique_ptr&& __u)
       {
     reset(__u.release());
     get_deleter() = std::move(__u.get_deleter());
     return *this;
       }
 
       template<typename _Up, typename _Ep, typename = typename
     std::enable_if
       <std::is_convertible<typename unique_ptr<_Up, _Ep>::pointer,
                    pointer>::value
        && !std::is_array<_Up>::value>::type>
     unique_ptr&
     operator=(unique_ptr<_Up, _Ep>&& __u)
     {
       reset(__u.release());
       get_deleter() = std::move(__u.get_deleter());
       return *this;
     }
 
       unique_ptr&
       operator=(nullptr_t)
       {
     reset();
     return *this;
       }
 
       // Observers.
       typename std::add_lvalue_reference<element_type>::type
       operator*() const
       {
     _GLIBCXX_DEBUG_ASSERT(get() != pointer());
     return *get();
       }
 
       pointer
       operator->() const
       {
     _GLIBCXX_DEBUG_ASSERT(get() != pointer());
     return get();
       }
 
       pointer
       get() const
       { return std::get<0>(_M_t); }
 
       deleter_type&
       get_deleter()
       { return std::get<1>(_M_t); }
 
       const deleter_type&
       get_deleter() const
       { return std::get<1>(_M_t); }
 
       explicit operator bool() const
       { return get() == pointer() ? false : true; }
 
       // Modifiers.
       pointer
       release()
       {
     pointer __p = get();
     std::get<0>(_M_t) = pointer();
     return __p;
       }
 
       void
       reset(pointer __p = pointer())
       {
     using std::swap;
     swap(std::get<0>(_M_t), __p);
     if (__p != pointer())
       get_deleter()(__p);
       }
 
       void
       swap(unique_ptr& __u)
       {
     using std::swap;
     swap(_M_t, __u._M_t);
       }
 
       // Disable copy from lvalue.
       unique_ptr(const unique_ptr&) = delete;
       unique_ptr& operator=(const unique_ptr&) = delete;
   };
 
   /// 20.7.12.3 unique_ptr for array objects with a runtime length
   // [unique.ptr.runtime]
   // _GLIBCXX_RESOLVE_LIB_DEFECTS
   // DR 740 - omit specialization for array objects with a compile time length
   template<typename _Tp, typename _Dp>
     class unique_ptr<_Tp[], _Dp>
     {
       typedef std::tuple<_Tp*, _Dp>     __tuple_type;
       __tuple_type          _M_t;
 
     public:
       typedef _Tp*          pointer;
       typedef _Tp           element_type;
       typedef _Dp                       deleter_type;
 
       static_assert(!std::is_pointer<deleter_type>::value,
             "constructed with null function pointer deleter");
 
       // Constructors.
       constexpr unique_ptr()
       : _M_t(pointer(), deleter_type())
       { }
 
       explicit
       unique_ptr(pointer __p)
       : _M_t(__p, deleter_type())
       { }
 
       unique_ptr(pointer __p,
       typename std::conditional<std::is_reference<deleter_type>::value,
           deleter_type, const deleter_type&>::type __d)
       : _M_t(__p, __d) { }
 
       unique_ptr(pointer __p,
          typename std::remove_reference<deleter_type>::type && __d)
       : _M_t(std::move(__p), std::move(__d))
       { static_assert(!std::is_reference<deleter_type>::value,
               "rvalue deleter bound to reference"); }
 
       /*  TODO: use delegating constructor */
       constexpr unique_ptr(nullptr_t)
       : _M_t(pointer(), deleter_type())
       { }
 
       // Move constructors.
       unique_ptr(unique_ptr&& __u)
       : _M_t(__u.release(), std::forward<deleter_type>(__u.get_deleter())) { }
 
       template<typename _Up, typename _Ep>
     unique_ptr(unique_ptr<_Up, _Ep>&& __u)
     : _M_t(__u.release(), std::forward<deleter_type>(__u.get_deleter()))
     { }
 
       // Destructor.
       ~unique_ptr() { reset(); }
 
       // Assignment.
       unique_ptr&
       operator=(unique_ptr&& __u)
       {
     reset(__u.release());
     get_deleter() = std::move(__u.get_deleter());
     return *this;
       }
 
       template<typename _Up, typename _Ep>
     unique_ptr&
     operator=(unique_ptr<_Up, _Ep>&& __u)
     {
       reset(__u.release());
       get_deleter() = std::move(__u.get_deleter());
       return *this;
     }
 
       unique_ptr&
       operator=(nullptr_t)
       {
     reset();
     return *this;
       }
 
       // Observers.
       typename std::add_lvalue_reference<element_type>::type
       operator[](size_t __i) const
       {
     _GLIBCXX_DEBUG_ASSERT(get() != pointer());
     return get()[__i];
       }
 
       pointer
       get() const
       { return std::get<0>(_M_t); }
 
       deleter_type&
       get_deleter()
       { return std::get<1>(_M_t); }
 
       const deleter_type&
       get_deleter() const
       { return std::get<1>(_M_t); }
 
       explicit operator bool() const
       { return get() == pointer() ? false : true; }
 
       // Modifiers.
       pointer
       release()
       {
     pointer __p = get();
     std::get<0>(_M_t) = pointer();
     return __p;
       }
 
       void
       reset(pointer __p = pointer())
       {
     using std::swap;
     swap(std::get<0>(_M_t), __p);
     if (__p != nullptr)
       get_deleter()(__p);
       }
 
       void
       reset(nullptr_t)
       {
     pointer __p = get();
     std::get<0>(_M_t) = pointer();
     if (__p != nullptr)
       get_deleter()(__p);
       }
 
       // DR 821.
       template<typename _Up>
     void reset(_Up) = delete;
 
       void
       swap(unique_ptr& __u)
       {
     using std::swap;
     swap(_M_t, __u._M_t);
       }
 
       // Disable copy from lvalue.
       unique_ptr(const unique_ptr&) = delete;
       unique_ptr& operator=(const unique_ptr&) = delete;
 
       // Disable construction from convertible pointer types.
       // (N2315 - 20.6.5.3.1)
       template<typename _Up>
     unique_ptr(_Up*, typename
            std::conditional<std::is_reference<deleter_type>::value,
            deleter_type, const deleter_type&>::type,
            typename std::enable_if<std::is_convertible<_Up*,
            pointer>::value>::type* = 0) = delete;
 
       template<typename _Up>
     unique_ptr(_Up*, typename std::remove_reference<deleter_type>::type&&,
            typename std::enable_if<std::is_convertible<_Up*,
            pointer>::value>::type* = 0) = delete;
 
       template<typename _Up>
     explicit
     unique_ptr(_Up*, typename std::enable_if<std::is_convertible<_Up*,
            pointer>::value>::type* = 0) = delete;
   };
 
   template<typename _Tp, typename _Dp>
     inline void
     swap(unique_ptr<_Tp, _Dp>& __x,
      unique_ptr<_Tp, _Dp>& __y)
     { __x.swap(__y); }
 
   template<typename _Tp, typename _Dp,
        typename _Up, typename _Ep>
     inline bool
     operator==(const unique_ptr<_Tp, _Dp>& __x,
            const unique_ptr<_Up, _Ep>& __y)
     { return __x.get() == __y.get(); }
 
   template<typename _Tp, typename _Dp>
     inline bool
     operator==(const unique_ptr<_Tp, _Dp>& __x, nullptr_t)
     { return __x.get() == nullptr; }
 
   template<typename _Tp, typename _Dp>
     inline bool
     operator==(nullptr_t, const unique_ptr<_Tp, _Dp>& __y)
     { return nullptr == __y.get(); }
 
   template<typename _Tp, typename _Dp,
        typename _Up, typename _Ep>
     inline bool
     operator!=(const unique_ptr<_Tp, _Dp>& __x,
            const unique_ptr<_Up, _Ep>& __y)
     { return !(__x.get() == __y.get()); }
 
   template<typename _Tp, typename _Dp>
     inline bool
     operator!=(const unique_ptr<_Tp, _Dp>& __x, nullptr_t)
     { return __x.get() != nullptr; }
 
   template<typename _Tp, typename _Dp>
     inline bool
     operator!=(nullptr_t, const unique_ptr<_Tp, _Dp>& __y)
     { return nullptr != __y.get(); }
 
   template<typename _Tp, typename _Dp,
        typename _Up, typename _Ep>
     inline bool
     operator<(const unique_ptr<_Tp, _Dp>& __x,
           const unique_ptr<_Up, _Ep>& __y)
     { return __x.get() < __y.get(); }
 
   template<typename _Tp, typename _Dp,
        typename _Up, typename _Ep>
     inline bool
     operator<=(const unique_ptr<_Tp, _Dp>& __x,
            const unique_ptr<_Up, _Ep>& __y)
     { return !(__y.get() < __x.get()); }
 
   template<typename _Tp, typename _Dp,
        typename _Up, typename _Ep>
     inline bool
     operator>(const unique_ptr<_Tp, _Dp>& __x,
           const unique_ptr<_Up, _Ep>& __y)
     { return __y.get() < __x.get(); }
 
   template<typename _Tp, typename _Dp,
        typename _Up, typename _Ep>
     inline bool
     operator>=(const unique_ptr<_Tp, _Dp>& __x,
            const unique_ptr<_Up, _Ep>& __y)
     { return !(__x.get() < __y.get()); }
 
   /// std::hash specialization for unique_ptr.
   template<typename _Tp, typename _Dp>
     struct hash<unique_ptr<_Tp, _Dp>>
     : public std::unary_function<unique_ptr<_Tp, _Dp>, size_t>
     {
       size_t
       operator()(const unique_ptr<_Tp, _Dp>& __u) const
       {
     typedef unique_ptr<_Tp, _Dp> _UP;
     return std::hash<typename _UP::pointer>()(__u.get());
       }
     };
 
   // @} group pointer_abstractions
 
 _GLIBCXX_END_NAMESPACE
 
 #endif /*  _UNIQUE_PTR_H */
